# print("hello world")
# print("hello world1")
# print("hello world2")
# print("hello world3")
# print("hello world4")




# name = "bingbing"
# age = 18
# sex = "女"
# print(f"我的姓名:{name},我的年龄:{age},我的性别:{sex}")





# 拼接两个字符串

# name = "shy"
# str = "nb"
# name = ''.join([name,str])
# print(name)




# len函数的实现

# str = "hello world"
# count = 0
# for i in str:
#     count += 1
#
# print(count)





# 链表反着打印

# arr = [1,2,3,4,5]
# for i in range(-1,-len(arr)-1,-1):
#     print(arr[i])

# arr = [1,2,3,4,5]
# for i in range(len(arr)-1,-1,-1):
#     print(arr[i])





# 查找链表中的元素的下表

# my_list = [1,2,3,4,5]
# index = my_list.index(3)
# print(index)





# 链表排序

# mylist = [1,3,2,4,5,6,7,8,9]
# mylist.sort()
# print(mylist)




# 在链表中插入元素

# mylist = [1,2,3,4,5]
# mylist.insert(1,6)
# print(mylist)




# 链表追加元素

# mylist = [1,2,3,4,5,6,7,8,9]
# mylist.append(10)
# print(mylist)




# 追加多个元素

# mylist = [1,2,3,4,5]
# mylist.extend([6,7,8,9])
# print(mylist)




# 删除指定下表的元素

# mylist = [1,2,3,4,5,6,7,8,9]
# del mylist[2]
# print(mylist)




# 利用pop删除元素

# mylist = [1,2,3,4,5,6,7,8,9]
# element = mylist.pop(2)
# print(element)
# print(mylist)




# 指定元素的删除

# mylist = [1,2,2,3,4,5]
# mylist.remove(2) # 会删除第一个出现的2
# print(mylist)




# 清空链表

# mylist = [1,2,3,4,5]
# mylist.clear()
# print(mylist)




# 统计链表中元素的数量

# mylist = [1,2,3,4,5,3]
# Count = mylist.count(3)
# print(Count)





# 在链表后加多个元素

# List = ['s','d']
# # List.extend("[.]")
# List = List + ['[','.',']']
# print(List)